The present invention generally relates to a manufacture control system and, more particularly, to a distributed control system and method for controlling the production of small items of manufacture, such as batteries.
Items of manufacture, and, in particular, small items of manufacture requiring multiple processes during their production and which are produced in large quantities, such as dry cell batteries, are completed by passing the articles through a series of individual apparatuses which are specifically designed to perform one or two processes. These processing machines are often stand-alone units which operate on a bulk input/bulk output basis. This type of system is labor intensive, and lacks the capability for adequate quality control, rapid maintenance, or tracking of the manufactured articles.
Current processing equipment which typically operates in an indexed manner has a single main drive motor which drives the indexer as well as driving the application heads performing the specific process. These various operations conducted by the machines are mechanically timed and are controlled by mechanical cams. Such mechanical timing is time-consuming to setup, is not flexible, and may lack precision. Any malfunction of these machines generally requires the entire machine to be pulled off-line for time-consuming repair, thus resulting in undesirable production efficiency.
The bulk-in/bulk-out manner in which these machines operate is such that the battery cans are extracted in random fashion from a bin thereby requiring proper orientation to begin the processing and are then output from the machine into another bin after processing. The processed cans are then transported in bulk to another processing station whereupon the bin extraction and article orientation functions are again repeated thus duplicating unnecessary handling and time consuming operations. Others of these machines operate on a theory of back pressure wherein the battery cans are stacked and urged to a processing station by applying a force to the backed up cans to force the articles through the processing machine. There must always be a supply of battery cans on the input side to maintain sufficient pressure to keep the ‘pump primed’ thereby facilitating processing throughput. Such methods of input and output preclude the tracking of individual battery cans during processing and between discrete machines. The manufacturer therefore loses information about individual cans between product assembly or processing steps. A consequence of the random input and output is a loss of quality control on individual articles with the result being that there is little to no process data available on the articles, and what data is available is not in alignment with quality control samples taken from the processing line.
At the conclusion of the quality control sampling, the machine is again stopped and again unloaded by hand. This time-consuming but necessary function often results in a significant loss of valuable production time in addition to the excessive labor costs associated therewith. Additionally, repeated starting and stopping of the machine induces variation in the production process which can adversely affect production quality.
The current mechanically controlled machines often include one or more cams to transfer desired time sequenced motion to the processing apparatuses mounted to the machine for a desired synchronized operation. In addition to the single drive motor driving the processing apparatus, the motor also operates and drives a large mass circular dial which transports the battery cans therearound to the individual process stations on the machine. Typically, these large mass dials require a significant percentage of the power consumed by the machine to accelerate and decelerate the dial during the indexing operations. Power thus expended contributes little ‘value added’ to the finished product. Also, the acceleration and deceleration of large mass dials requires a significant portion of the total time of operation which therefore severely limits the throughput of the processing machines.
The aforementioned current processing equipment employs separately controlled process stations in which battery cans were randomly dumped from one machine to another, thereby eliminating any ability to track a given battery can. Additionally, in order to conduct experimental process operations, conventional manufacturing systems commonly require that the normal system operation first be shutdown, the experimental equipment then be installed, and the experimental process thereafter conducted. Once the experimental operation is finished, the conventional system is reconfigured for normal article manufacturing. Thus, experimental processing required extensive shutdown time and labor to reconfigure the system and conduct the experimental process.
Therefore, there is a desire and need in industry and particularly in dry cell battery processing for a processing system which can operate at increased throughput and which eliminates unnecessary handling and duplicative operations to be performed on the manufactured articles. The needed processing system has the additional characteristics of being flexible, permitting off-line set-up and calibration, the ability to be quickly deployed, and capable of rapidly incorporating product design changes. Such a system is also desired to more efficiently monitor quality control on processes, including the capability of tracking a single item of manufacture through the processing system, and also the ability to test new processes and processing equipment for a comparative analysis of articles of manufacture processed normally with articles of manufacture processed with one or more test processes.
Also, it is desirable to provide for a processing system that allows for battery cans to be tracked and accounted for throughout the entire processing operation. Further, it is desirable to provide for such a processing system that allows for easy experimental processing that does not require excessive system shutdown and labor.
Further, reduced manufacturing cost and increased processing operation efficiencies are desirable to produce a cost-effective product. The added costs associated with conventional production line setup, downtime and maintenance has created the need for creative control strategies that may reduce cost to provide a more cost effective product. Automated manufacturing control systems typically employ software that is dependent on a particular computer operating system and is designed to operate a predefined production line configuration. It is desirable to provide a distributed control system that is not dependent on a particular computer operating system software, provides flexible processing capability, and is able to control multiple production line configurations with minimal reconfiguration. It is also desirable to provide a distributed control system that may continue to control production of material in the event that a process control device, such as a processor fails to perform as configured, so as to reduce processing downtime and incur less added cost. Further, there is a need for control software that is flexible to allow for use with various control systems for controlling different types of production machinery, thereby eliminating the need for dependence on the supplier of a particular hardware or software configuration.